During the War of 3039, the Heavy Guards remained on New Avalon while the rest of their Brigade took part in the invasion of the Combine. [8] The decision to keep them on New Avalon may have been influenced by the Death Commando attack on the under-defended capital during the Fourth Succession War. (An action actually committed by the ComGuard.)

Afterward, the Heavy Guards would eventually return to Galax. At the start of the FedCom Civil War, they were briefly stranded there due to Katherine Steiner-Davion stripping them of their transport.[14] As a result, they were unable to prevent the destruction of the 1st Davion Guards on New Avalon. They later joined Prince Victor and his allies for the Second Battle of New Avalon, landing on the continent of Brunswick behind twelve confiscated Conquistador-class DropShips[15], where they finally removed Katherine from power. The Guards played a critical role, destroying Katherine's potential escape transport in a drive that essentially destroyed the unit for a time.[16] After the Civil War, the Heavy Guards kept four of the Conquistador DropShips.[17] Orders transferring the Heavy Guards to Kathil had been arranged[18], but the Heavy Guards never relocated there.

After the end of the Jihad the Davion Heavy Guard was swiftly rebuilt. Though they are headquartered on New Avalon for administrative purposes, the Heavy Guard has been broken down into two-company mixed units. These smaller commands have been stationed on dozens of worlds within thirty light years of New Avalon and are working to rebuild the planetary militias on these worlds.[21] A cadre from the Guards were also detached to help defend Layover, another important military-industrial world.[22]

Between 3080 and 3084 the Davion Heavy Guards deployed to dozens of worlds to rebuild their militia commands. Training against one of the best commands of the AFFS quickly sharpened the skills of these new defenders. The Heavy Guards rotated to Kathil in 3085 and continued their training regime in the Capellan March. As part of this training effort, the Heavy Guards have a regiment of conventional fighters assigned to them in addition to the double-sized AeroSpace Fighter contingent common to Davion Guards RCTs.[23] The Heavy Guards have also used their training experience to mentor the 1st NAIS Cadet Cadre, which was also assigned to Kathil.[24]

The Davion Heavy Guards was one of the regiments destroyed on Palmyra during the catastrophic losses taken by the Armed Forces of the Federated Suns during the DCMS invasion of the Draconis March. Despite the regiment being shattered, some survivors attempted to continue to fight; one such individual was CaptainBenjamin Horn, a company commander who lost half of his company in the initial assault but who went on to conduct a guerrilla campaign against the DCMS forces on the planet. Leading the remains of his company from his Vulpes, Horn became adpet at luring Combine lances into long-range ambushes using emissions from his Guardian ECM Suite. Horn scored four kills himself before a company from one of the Sword of Light regiments managed to catch him and his companions in a battle against a cliff face, leaving them with no avenue to retreat. Horn's soldiers fought to the last man, taking eight Sword of Light 'Mechs with them before the last man fell.[25]

The Davion Heavy Guards are at eighty percent of their pre-Jihad strength. Unfortunately they are scattered in small two company units across at least two dozen worlds performing cadre duties. Once their planetary militia units are up to speed it is likely the Davion Heavy Guards will relocate back to New Avalon.[21]

During the Star League Era, the Heavy Guards may use the Banking the Initiative, Forcing the Initiative, and Overrun Combat Force Specific Abilities. In role-playing campaigns, members of the Heavy Guards gain a +3 reputation trait and a +5 connections trait for as long as they're in the Heavy Guards.[36]

In 3062 the Heavy Guards can use Overrun Combat, Forcing the Initiative, and Banking the Initiative. When randomly assigning lance weight, add a +3 modifier to the Random Lance Weight roll. Characters in A Time of War rules receive a 2 TP Good Reputation and Well Connected/New Avalon traits for as long as they're assigned to the Heavy Guards, but these traits are lost when the character transfers out. ATOW characters assigned to the armor brigade receive 5 XP per month in either Tactics/Land or Strategy skills.[37]

↑Masters and Minions: The StarCorps Dossiers, p. 46 Davion Guards - Athena Davion-Ross promotion to command of Heavy Guards after promotion of Jon Davion's promotion after the Battles of New Avalon concluded in 3074.